Nitrides of indium (In), gallium (Ga), and aluminum (Al) and compounds thereof have many applications, including high-power and light-emitting devices. By moving to one dimensional, i.e. nanoscale, materials, a host of new applications become available.
Current nanoscale GaN technology is based on nanowires grown either by metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). These nanoscale materials are defined by having very large surface to volume ratios. When reducing the material to this scale, surface effects can begin to dominate the material properties and degrade performance. For example, in optical applications, the large surface area can cause photon scattering, while the small size also restricts the charge carrying capacity of the material.
One method for solving these problems involves using GaN material on a macro-scale, in the form of millimeter-scale filaments, also known as whiskers. Such whiskers may bridge the gap between bulk and nanoscale GaN. In this case, the material is more representative of the bulk, can carry larger charges, and should show less phonon scattering. In addition, due to their larger size, the whiskers are easier to manipulate. Growing the whiskers from solution also avoids the residual metal catalysis beads found at the tip of nanowires and allows for crystalline perfection.